Submerged electric heater.



B. FALKBNBERG` SUBMERGBD ELECTRIC HEATER.

APPLIOATNN FILED JAN. s1, 1911.

1,092,523. 'Famed Apr; 1914 UNITED. STATES PATENT OFFICE,

BJARNE FALKENBERG, OF ONTARIO, CALIFORNIA, ASSIG-NOR T0 PACIFIC ELECTRIC HEATING COMPANY, OF ONTARIO, CALIFORNIA, A CORPORATION '0F CALIFORNIA,

SUBMERGED ELECTRIC HEATER.

To all whom t may concern Be it known that I, BJARNE FALKENBERG, a subject of the King. of Norway, residing at Ontario, in the county of San-Bernardino and State of California, have invented a new and useful Submerged Electric Heater, of which the following is a specication.

This invention relates to submerged electric heaters wherein the heater is immersed in liquid to be heated, and the main object of the invention is to cause'the heating of the liquid to commence sooner after the current is turned on than heretofore. In this type of heater the heating element is submerged in the liquid to .be heated, and the liquid is' conducted in an annular stream along the heating unit and subjected to theheat thereof, but, owing to the relatively large lvolume of unheated liquid whichsurrounds theinular stream of liquid, 4the temperature of the latter is kept down on account of the absorption -of heat from it' by the surrounding body of liquid. To obviate this I provide a` heat insulating means between this annular stream of liquid vw-hich is being heated andthe main body of the liquid which prevents heat from the annular stream being absorbed by or transmitted to l the largerbody of liquid, and thereby cau-se the annular stream to be very quickly heated to the desired temperature and ready for use much more quickly after starting the heater in operation than `has hereto ore been possible without the heat insulating means between the liquid being heated and the main body of liquid. In practice Ihave found 'that this construction will cause the stream to be heated to the de- A sired degree in from' twenty to twenty-five seconds after turning on the current; while,

without the heat insulating element bet-Ween the main body of liquid and the -annular streambeing heated, seven minutes was required to raise the stream to the same degree of temperature. 1 Obviously, evenvwhere the desired degree of temperature was reached slowly, a greater amo-unt o-f the liquid would be heated, but in this type of heater the irnport-ant thing is to have a relatively small amount of the .liquid heated very quickly and to maintain this rate of lheating during the operation of the heater.

l lWhen the invention is applied to one of its most important uses, as in a coffee percolator, the prime requisite is to start the Specification of Letters Patent. l ,Application led January 31, 1911..

Patented Apr. 7, 1914;;

seriamaeoa'zsa y -percolation quickly.l Tol do this it is not necessary that the entire volume of water be quickly heated throughout, but it is neces- .sary that a small-amount of it vbe quickly heated and this is what the present invention accomplishes by reason of the insula tion of that p-art of the liquid being heated from the largerl volume which is not being heated.

Heretofore in coffee percolators the heating element has been arranged below the bottom of the receptacle containing, the .l

water, but in the present invention I locate the heating unit within'the liquid so that,y A

the heating unit is surrounded b y 'a much larger amount of the water than where the heat-ing element is below the bottom and for that reason, practically all o f the heat.v

which is generated by the heating element must be absorbed by the liquid surrounding it, and in addition to the economyre-` sult-ing from the utilization of all of the heat generated, there is the further advantage of. the water being heated more quickly.l A further advantage of this construction is that as the heating element is located within the water receptacle, the percolator is a self-contained unitary construc-v tion with no parts to become lost or disar-v ranged and it may be readily placed 'on the table. The location of the heating element being within the body of liquid. does not add to the height of the receptacle and therefore the percolator stands lower than heretofore. l

In'thedrawings I have shown the invention as applied to a coffee' percolator, al-

though, as above stated, its use'v is not to be thus restricted, and referring thereto:

Figure l is a vertical cross'sectional view through vthe percolator.v Fig. 2 is a hori zontal section on line @i2-:v2 Fig. 1. Y

l designates the main liquid receptacle which isv mounted on a base 2.

3 designates the coffee receptacle. The heating unit comprises, in the present embodiment, a resistance wire 4 which is wound oyer a drum 5 of lava orother nonconducting material, lava being preferred by reason of its non-heat-conducting and non-electrical-conducting properties. This heating unit is surrounded by a layer of mica 6 and the heating unit thus formed is inclosed in a brass housing 7, the latter having a flange Sat its lower end which l vio lzo

rests against the bottom of the main receptacle 1 and a nut 9 is screwed on the lower end of the housing 7 and secures the base 2 to the vreceptacle 1 and at the same time holds the housing Yin position, there being packing 10 between the main receptacle 1 and base 2 which prevents leakage. Surrounding the housing 7 is a shell 11 which forms a space 12 next to the housing 'i and the space 12 communicates with a vertical tube 13 connected to the top` of the shell 11, the tube 13 extending up through the codee receptacle 3. Surrounding the shell 11 is a jacket let .with an air chamber 15 between the jacket 14 and shell 11 heat insulating means surrounding the shell 11.v Liquid from the main receptacle 1 is furnished to the lower part of the chamber 12 by a series of short tubes 1G which pass through the jacket 111 and shell 11. The ends 17 and 18 and the wire 4f are connected with a switchplug 19 which is arranged within the base 2, there being a false bottom 20 within the base 2 which prevents the arts within from being tampered with. In operation, the liquid.v is placed within the main receptacle 1 and the'codee is placed wit-hin the receptacle 3. rent is turned on, the resistance Wire 4 becomes highly heated, the inward radial passage of the heat being resiste-d by the drum 5, while the brass housing 7, being a good conductor of heat, conducts the heat thus generated directly to the annular stream of waterwhich lies within the chamber 12. The water inthe chamber 12 being distributed in a thin film and in contact with the hot brass housing 7 becomes heated to the point where percolation will commence in a few secondsl after the current is turned on and produces an upward dow through the tube 13. The yheated water overHowS from the tube 13` and percolates down through the coffee within the receptacle 3 and thence returns to the main'body of liquid .within the' receptacle 1. r1`he4 heat.

which reaches the cylindrical column of waterl within the chamber 12 is retained. wholly by the water therein, as the deadl air y liquid from outside'the jacket to the in-v chamber 15 which' surrounds it prevents any heat passing from the water in chamber'12 to the main body'of liquid surrounding the jacket 14. I have found in practice that where the main body of liquid within the receptacle 1 comes into direct contact with the shell 11, it absorbs heat from'the liquid which is within the chamber 12, so that the latter liquid does not become heated much ,faster than the surrounding body of liquid,

which forms a When electric cur-` l'day of January, 1911. y

aoeaeaa in such a construction about seven minutes being required to raise the temperature of the liquid to .the point where percolation will commence; but with the air chamber 15, the heat which istransmittedto the liquid within the chamber 12 is retained by that liquid and being prevented from passing to the main body of liquid, under such conditions in from twenty to twenty-five seconds afterpstarting the heater, percola tionwill commence.

'What l claim is:

1. ln an electric liquid heater, a main re ceptacle, a housing with a flange resting against the bottom of the main receptacle, a basejthrough which the lower end of the housing'p'rojects, a nut screwed to the housing and securing saidbase, a shell surrounding saidv lio-using and forming a liquid chamber, a jacket surrounding said shell and forming an air chamber, an insulating drum within the housing, resistance wire wound on the drinn, a tube extending up from the shell, another receptacle in the upper part of the main receptacle through which the tube passes, and aswitch plug within 'the base connected with the resistance wire.

2. An electric liquid heater comprising a drinn of non-conductive material, resist- 'ance wire 'wound thereon, a cylindrical brass housing of heat conducting mapt'ial surrounding the wire, a shell around the housing forming a liquid chamber between the shell and housing, a tube extending up `from the liquid chamber, and a jacket surrounding the shell forming an air space between the jacket and shell.

3. lAn electric liquid heater comprising a drum of non-conductive material, resistance wire wound thereon, a cylindrical brass housing of heat conducting material surrounding the wire,

a shell around the hous' infr forming a liquid chamber between the she l and housing, a jacket surrounding. the

shell forming an air space between the jacket vand shell, a tube extending up from said shell, and a series of tubes extendingl through saidjacket and shell to convey terior of the shell..

In testimony whereof, l have hereunto set my hand at Ontario, California, this 25th :BJARNE rALKENBERd 

